The invention relates generally to an apparatus useful in magnetic resonance (MR) imaging and, more particularly, to a table for transporting a patient from a preparation room to an MR examination room. In the MR examination room, the table can be used to position the patient within and retrieve the patient from, the bore of the MR imaging system.
When a substance such as human tissue is subjected to a uniform magnetic field (polarizing field B0), the individual magnetic moments of the spins in the tissue attempt to align with this polarizing field, but precess about it in random order at their characteristic Larmor frequency. If the substance, or tissue, is subjected to a magnetic field (excitation field B1) which is in the x-y plane and which is near the Larmor frequency, the net aligned moment, or “longitudinal magnetization”, MZ, may be rotated, or “tipped”, into the x-y plane to produce a net transverse magnetic moment Mt. A signal is emitted by the excited spins after the excitation signal B1 is terminated and this signal may be received and processed to form an image.
When utilizing these signals to produce images, magnetic field gradients (Gx, Gy, and Gz) are employed. Typically, the region to be imaged is scanned by a sequence of measurement cycles in which these gradients vary according to the particular localization method being used. The resulting set of received NMR signals are digitized and processed to reconstruct the image using one of many well known reconstruction techniques.
Due to the nature of some MR scans, there is a patient population (e.g., children age 7 and below, claustrophobic patients, patients with Parkinsons'Disease, some elderly patients, etc.) that can benefit from anesthesia and other support systems to assist the patients to remain stationary for long periods of time throughout the MR scans. Generally, anesthesia systems include various pieces of equipment to anesthetize the patient, support or control respiration, and keep the patient in that state until some medical procedure is completed.
Anesthesia systems generally comprise a plurality of pressure regulators, vaporizers, gas mixing devices and flow control devices. The vaporizer converts a liquid anesthetic to gaseous form. The gas is then combined with life support gases and delivered to the patient, usually through a facemask or similar device. The anesthesia machine also handles various monitoring functions and gas supplies depending on the breathing circuit being used. The patient breathing circuit conveys the anesthetic (in gaseous form) to the patient and typically has an inspiratory limb tube through which gases are delivered to the patient and an expiratory limb tube through which exhaled gases are taken from the patient.
The time needed to set up and tear down the anesthesia and other support equipment can add as much as 30 to 40 minutes to MR exam times. Equipment contributing to the setup and tear-down processes may be, for example, an anesthesia machine, an IV pump, and a monitoring module, all of which need to be connected to the patient via associated hardware such as breathing tubes, IV lines, and monitoring cables. Typically these various cables, lines, and tubes lie on the floor near the table where they are susceptible to damage from traffic such as a mobile patient table, medical personnel, or the like. In cases where the setup and tear-down occur outside of the MR examination room, the separate equipment including the cables, lines, and tubes must be moved in and out of the MR examination room, which increases the chances for damaging the cables, lines, and tubes and may require extra personnel to transport the various support equipment and associated hardware to and from the MR examination room.
It would therefore be desirable to have a patient transport apparatus capable of transporting an anesthetized patient and support equipment to and from an MR examination room that reduces opportunities for equipment damage and simplifies transportation of the anesthetized patient and support equipment.